§ 4. The next of the common divisions of Propositions is into Universal, Particular, Indefinite, and Singular: a distinction founded on the degree of generality in which the name, which is the subject of the proposition, is to be understood. The following are examples:
All men are mortal—Universal.
Some men are mortal—Particular.
Man is mortal—Indefinite.
Julius Cæsar is mortal—Singular.
The proposition is Singular, when the subject is an individual name. The individual name needs not be a proper name. “The Founder of Christianity was crucified,” is as much a singular proposition as “Christ was crucified.”
When the name which is the subject of the proposition is a general name, we may intend to affirm or deny the predicate, either of all the things that the subject denotes, or only of some. When the predicate is affirmed or denied of all and each of the things denoted by the subject, the proposition is universal; when of some undefined portion of them only, it is particular. Thus, All men are mortal; Every man is mortal; are universal propositions. No man is immortal, is also a universal proposition, since the predicate, immortal, is denied of each and every individual denoted by the term man; the negative proposition being exactly equivalent to the following, Every man is not-immortal. But “some men are wise,” “some men are not wise,” are particular propositions; the predicate wise being in the one case affirmed and in the other denied not of each and every individual denoted by the term man, but only of each and every one of some portion of those individuals, without specifying what portion; for if this were specified, the proposition would be changed either into a singular proposition, or into a universal proposition with a different subject; as, for instance, “all properly instructed men are wise.” There are other forms of particular propositions; as, “Most men are imperfectly educated:” it being immaterial how large a portion of the subject the predicate is asserted of, as long as it is left uncertain how that portion is to be distinguished from the rest.3
When the form of the expression does not clearly show whether the general name which is the subject of the proposition is meant to stand for all the individuals denoted by it, or only for some of them, the proposition is, by some logicians, called Indefinite; but this, as Archbishop Whately observes, [pg 072] is a solecism, of the same nature as that committed by some grammarians when in their list of genders they enumerate the doubtful gender. The speaker must mean to assert the proposition either as a universal or as a particular proposition, though he has failed to declare which: and it often happens that though the words do not show which of the two he intends, the context, or the custom of speech, supplies the deficiency. Thus, when it is affirmed that “Man is mortal,” nobody doubts that the assertion is intended of all human beings; and the word indicative of universality is commonly omitted, only because the meaning is evident without it. In the proposition, “Wine is good,” it is understood with equal readiness, though for somewhat different reasons, that the assertion is not intended to be universal, but particular.4 As is observed by Professor Bain,5 the chief examples of Indefinite propositions occur “with names of material, which are the subjects sometimes of universal, and at other times of particular predication. ‘Food is chemically constituted by carbon, oxygen, etc.,’ is a proposition of universal quantity; the meaning is all food—all kinds of food. ‘Food is necessary to animal life’ is a case of particular quantity; the meaning is some sort of food, not necessarily all sorts. ‘Metal is requisite in order to strength’ does not mean all kinds of metal. ‘Gold will make a way,’ means a portion of gold.”